Day.

The meaning of the term "day" as used in Biblical Creation is a source of debate. Some Biblical literalists believe that God literally created the Earth in 7 24-hour blocks of time.

Others take a more liberal approach, and probably the only reasonable approach as we study scripture and Genesis closely.

Sources for this post are Genesis in Space and Time (which is about the flow of Biblical history) and The Beginning of Wisdom (graciously recommended by a good friend).

Francis A. Schaeffer in Genesis in Space and Time says that the term day as related to creation must be held with openness. He uses the King James version of the Bible, and then colloquializes (totally not a word) the language.

• In Genesis 5:2 we read: "Male and female created he them; and blessed them, and called their name Adam, in the day when they were created." As it is clear that Adam and Eve were not created simultaneously, day in Genesis 5:2 does not mean a period of 24 hours.
  

Schaeffer explains that the term day used in Hebrew could denote an era just as it can in English. (e.g., Back in my day). He then goes on to say

• the simple fact is that day in Hebrew (just as in English) is usedd in three separate senses, to mean: (1) twenty-four hours, (2) the period of light during the twenty-four hours, and (3) an indeterminate period of time.
  

Finally, Schaeffer makes the point that this is not a thing that can really be debated because there are no clearly defined terms upon which to debate. But it seems self-evident, unless you are gung ho on a literal interpretation of the Bible--which some are--that day in this sense doesn't mean a 24 hour period.

A point made obvious in Leon Kass' The Beginning of Wisdom which I think closes the issue to any debate whatsoever is found by a direct reading of the scripture:

• And God said, "Let there be light," and there was light. God saw that the light was good, and he separated the light from the darkness. God called the light "day," and the darkness he called "night." And there was evening, and there was morning--the first day. (Gen 1:3-5). (This was on the First Day).
  

And then...

• And God said, "Let there be lights in the expanse of the sky to separate the day from teh night, and let them serve as signs to mark seasons and says and years, and let them be lights in the expanse of the sky to give light on the earth." And it was so. God made two great lights--the greater light to goern the day and the lesser light to govern the night. He also made the stars. (This was on the Fourth Day).
  

So... we had light before we had stars. The Sun is a star. We had light before we had the Sun. On the third day we even had vegetation before we had the Sun. The main point though is that we mark the times and our days in relation to the Sun. If we had a First Day, a Second Day, and a Third Day all before we had the Sun, this would seem to definitively mean that the term day means something other than a 24 hour period.

I realize this is not a major point of curiosity or contention to most people, but this certainly does re-work the way we think about the Creation story altogether, a not insignificant implication in this is the age of the Earth. But New Earthers vs. Old Earthers is another debate for another day.